Thermal control system

ABSTRACT

A thermal control unit for delivering temperature-controlled fluid to one or more patient therapy devices (e.g. pads, blankets, etc.) that are in contact with a patient is disclosed. The thermal control unit includes a fluid circuit with an inlet and outlet, a reservoir, a heat exchanger, a pump, and a controller. The thermal control also includes any one or more of the following: (1) an air eliminator with an air filter for filtering air vented from the fluid circuit to the ambient surroundings; (2) a plug that moves in response to changing fluid levels and that fluidly isolates the air filter from the fluid; (3) a second air filter coupled to the reservoir; (4) a check valve to prevent fluid from back flowing into the reservoir; and/or (5) a liquid filter coupleable to the reservoir to filter liquid entering or exiting the reservoir.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional patent applicationSer. No. 62/361,124 filed Jul. 12, 2016, by inventor Gregory Taylor andentitled THERMAL CONTROL SYSTEM, the complete disclosure of which isincorporated herein by reference.

BACKGROUND

The present disclosure relates to a thermal control system forcontrolling the temperature of circulating fluid which is delivered toone or more thermal pads positioned in contact with a patient.

Thermal control systems are known in the art for controlling thetemperature of a patient by supplying temperature-controlled fluid toone or more pads, blankets, or similar structures, that are positionedin contact with, or adjacent to, a patient. The temperature of the fluidis controlled by a thermal unit that provides fluid to the pads orblankets. After passing through the pads or blankets, the fluid isreturned to the control unit where any necessary adjustments to thereturning fluid temperature are made before being pumped back to the pador blanket. In some instances, the temperature of the fluid iscontrolled to a target fluid temperature, while in other instances thetemperature of the fluid is controlled in order to effectuate a targetpatient temperature. When controlling a patient's temperature, a patienttemperature probe may be attached to the control unit in order toprovide patient temperature readings as feedback to the control unit sothat it can make the necessary temperature adjustments to thecirculating fluid.

SUMMARY

The present disclosure provides various improved aspects to a thermalcontrol system. In one embodiment, the present disclosure includes athermal control unit that substantially prevents the escape ofaerosolized fluid contained within the thermal control unit and used tocontrol the temperature of the patient. In one or more embodiments, thepresent disclosure includes a thermal control unit that helps preventspillage of the fluid used to control the temperature of the patient,such as spillage due to back flow of the fluid into a reservoir in thethermal control unit. In one or more embodiments, the present disclosureincludes a thermal control unit that facilitates the use of clean fluidin the thermal control unit.

According to one embodiment, a thermal control unit is provided thatincludes a fluid circuit, a reservoir, a heat exchanger, a pump, an aireliminator, an air filter, and a controller. The fluid circuit includesa fluid outlet adapted to couple to a fluid supply line and a fluidinlet adapted to couple to a fluid return line. The reservoir suppliesfluid to the fluid circuit. The heat exchanger changes a temperature ofthe fluid in the fluid circuit. The pump circulates the fluid suppliedby the reservoir through the fluid circuit. The air eliminator vents airfrom the fluid circuit to the ambient surroundings. The controllercontrols the heat exchanger such that a temperature of the circulatingfluid is adjusted toward a desired temperature. And the air filtercouples to the air eliminator and filters the air vented to the ambientsurroundings by the air eliminator.

According to another embodiment, a thermal control unit is provided thatincludes a fluid circuit, a reservoir, a heat exchanger, a pump, an aireliminator, an air filter, a plug, and a controller. The fluid circuitincludes a fluid outlet adapted to couple to a fluid supply line and afluid inlet adapted to couple to a fluid return line. The reservoirsupplies fluid to the fluid circuit. The heat exchanger changes atemperature of the fluid in the fluid circuit. The pump circulates thefluid supplied by the reservoir through the fluid circuit. The aireliminator vents air from the fluid circuit to the ambient surroundings.The plug has a position that varies in response to a level of fluid inthe thermal control unit. The plug is adapted to fluidly isolate the airfilter from the fluid in the thermal control unit if the level of fluidin the thermal control unit exceeds a threshold. The controller controlsthe heat exchanger such that a temperature of the circulating fluid isadjusted toward a desired temperature.

According to another embodiment, a thermal control unit is provided thatincludes a fluid circuit, a removable reservoir, a heat exchanger, apump, an air eliminator, a check valve, and a controller. The fluidcircuit includes a fluid outlet adapted to couple to a fluid supply lineand a fluid inlet adapted to couple to a fluid return line. Thereservoir supplies fluid to the fluid circuit. The heat exchangerchanges a temperature of the fluid in the fluid circuit. The pumpcirculates the fluid supplied by the reservoir through the fluidcircuit. The air eliminator vents air from the fluid circuit to theambient surroundings. The check valve is positioned between theremovable reservoir and the fluid circuit and is adapted to preventfluid from flowing out of the fluid circuit and into the removablereservoir. The controller controls the heat exchanger such that atemperature of the circulating fluid is adjusted toward a desiredtemperature.

According to another embodiment, a thermal control unit is provided thatincludes a fluid circuit, a reservoir, a heat exchanger, a pump, and acontroller. The fluid circuit includes a fluid outlet adapted to coupleto a fluid supply line and a fluid inlet adapted to couple to a fluidreturn line. The reservoir supplies fluid to the fluid circuit andincludes an air filter in fluid communication with an interior of thereservoir. The air filter filters air escaping from the interior of thereservoir. The heat exchanger changes a temperature of the fluid in thefluid circuit. The pump circulates the fluid supplied by the reservoirthrough the fluid circuit, and the controller controls the heatexchanger such that a temperature of the circulating fluid is adjustedtoward a desired temperature.

According to still another embodiment, a thermal control unit isprovided that includes a fluid circuit, a reservoir, a heat exchanger, apump, and a controller. The fluid circuit includes a fluid outletadapted to couple to a fluid supply line and a fluid inlet adapted tocouple to a fluid return line. The reservoir supplies fluid to the fluidcircuit and includes a liquid filter in fluid communication with aninterior of the reservoir. The liquid filter filters the fluid when thefluid is poured into the reservoir. The heat exchanger changes atemperature of the fluid in the fluid circuit. The pump circulates thefluid supplied by the reservoir through the fluid circuit, and thecontroller controls the heat exchanger such that a temperature of thecirculating fluid is adjusted toward a desired temperature.

According to other aspects, the plug sealingly engages an aperture whenthe plug rises past a threshold height, wherein the aperture ispositioned between the air filter and the fluid.

In some embodiments, one or two air filters are included that have poresizes no greater than 0.2 microns.

The reservoir is adapted to be lifted out of the thermal control unitwithout leaking fluid, in at least some embodiments.

An air and liquid filter is included in some embodiments that is adaptedto filter the fluid when the fluid is poured into the removablereservoir and to filter air escaping from the removable reservoir to theambient surroundings. The air and liquid filter may be integrated into aremovable lid adapted to be selectively attached to, and detached from,the removable reservoir.

According to another embodiment, a thermal control unit is provided thatincludes a fluid circuit, a heat exchanger, a pump, and a controller.The fluid circuit includes a fluid outlet adapted to couple to a fluidsupply line and a fluid inlet adapted to couple to a fluid return line.The heat exchanger is adapted to change a temperature of fluid in thefluid circuit. The pump circulates fluid through the fluid circuit. Thecontroller communicates with a disinfection unit and controls the pumpin order to pump disinfecting fluid through the fluid circuit. Thecontroller also controls a drain to drain the disinfecting fluid fromthe fluid circuit based upon communication received from thedisinfection unit.

According to other aspects, the controller controls the pump such thatthe disinfecting fluid flows through the fluid circuit for apredetermined amount of time before draining the disinfecting fluidand/or controls the heat exchanger such that a temperature of thedisinfecting fluid is controlled toward a target temperature whileflowing through the fluid circuit.

In some embodiments, the thermal control unit is adapted to receive thedisinfecting fluid via the fluid inlet and to drain the disinfectingfluid via the fluid outlet.

The controller is further adapted to control the pump and the heatexchanger in order to deliver temperature-controlled non-disinfectingfluid to a thermal pad via the fluid outlet and to receive thetemperature-controlled non-disinfecting fluid back from the thermal padvia the fluid inlet.

In some embodiments, a drain valve is also included that is incommunication with the controller. The controller drains thedisinfecting fluid by opening the drain valve.

Before the various embodiments disclosed herein are explained in detail,it is to be understood that the claims are not to be limited to thedetails of operation or to the details of construction, nor to thearrangement of the components set forth in the following description orillustrated in the drawings. The embodiments described herein arecapable of being practiced or being carried out in alternative ways notexpressly disclosed herein. Also, it is to be understood that thephraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use of“including” and “comprising” and variations thereof is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items and equivalents thereof. Further, enumeration may beused in the description of various embodiments. Unless otherwiseexpressly stated, the use of enumeration should not be construed aslimiting the claims to any specific order or number of components. Norshould the use of enumeration be construed as excluding from the scopeof the claims any additional steps or components that might be combinedwith or into the enumerated steps or components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a thermal control system that may beused to provide thermal treatment to a patient;

FIG. 2 is a perspective view of a thermal control unit of the thermalcontrol system of FIG. 1;

FIG. 3 is block diagram of the thermal control unit of FIG. 2;

FIG. 4 is a side, elevation view of an air extraction unit of thethermal control unit of FIG. 2;

FIG. 5 is a side, elevation view of an alternative embodiment of aremovable fluid reservoir that may be used with a thermal control unit,such as, but not limited to, the thermal control unit of FIG. 2;

FIG. 6 is a side, elevation view of an alternative thermal control unithaving an integrated fluid reservoir;

FIG. 7 is a side, elevation view of another alternative embodiment of afluid reservoir that may be used with a thermal control unit, such as,but not limited to, the thermal control unit of FIG. 2;

FIG. 8 is a side elevation view of a fluid container adapted to beselectively coupled to the fluid reservoir of FIG. 7;

FIG. 9 is an elevation view of a thermal control unit disinfectionsystem according to another embodiment of the present disclosure; and

FIG. 10 is a block diagram of a disinfection station of the disinfectionsystem of FIG. 9.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A thermal control system 20 according to one embodiment of the presentdisclosure is shown in FIG. 1. Thermal control system 20 includes athermal control unit 22 coupled to one or more thermal therapy devices32. The thermal therapy devices 32 are wrapped around different portionsof a patient 88, such as, but not limited to, the patient's torso andlegs. The thermal control unit 22 delivers temperature controlled fluidto the thermal therapy devices 32 in order to control a temperature ofthe patient.

Thermal control unit 22 includes a plurality of fluid outlet ports 24, aplurality of fluid inlet ports 26, and a plurality of patienttemperature probe ports 28 (FIGS. 2-3). The outlet ports 24 are eachadapted to be fluidly coupled to a corresponding fluid supply line orhose 30 a (FIG. 1) that transports a thermal fluid from the thermalcontrol unit 22 to a connected patient thermal therapy device 32, whichmay be a pad, a blanket, a vest, or other structure. For purposes of thefollowing written description, thermal therapy device 32 will bereferred to as a thermal pad 32, but it will be understood by thoseskilled in the art that thermal pad 32 is not limited to pads, butincludes other types of patient thermal therapy devices. The inlet ports26 define fluid inlets into control unit 22 and are each adapted to befluidly coupled to a corresponding fluid return line or hose 30 b thatreturns the thermal fluid from the thermal pad 32 back to the controlunit 22. The fluid inside of control unit 22 is therefore pumped bycontrol unit 22 in a circuit that starts at control unit 22, continuesthrough supply lines 30 a to the thermal pads 32, and returns back tothe control unit 22 by way of return lines 30 b.

Thermal control unit 22 of FIGS. 1-3 circulates the fluid through threefluid circuits. Each fluid circuit is defined by control unit 22, one ofthe connected thermal pads 32, and the corresponding pair of supply andreturn lines 30 a and 30 b. In the embodiment shown in FIGS. 1-3, thefluid that returns to control unit 22 from each return line 30 b ismixed in a common return or inlet manifold 34, and the temperature ofthat mixed fluid is controlled to a single desired temperature (whichmay vary, as will be described more below) by passing it through a heatexchanger 36 (described below). The temperature-controlled fluid is thenpumped to an outlet manifold 38 having three outlet ports 24 fordelivery to each supply line 30 a, so that the temperature of the fluiddelivered to each outlet port 24 is the same. In this embodiment, eachfluid circuit is supplied with fluid at outlet ports 24 that is at thesame temperature. In an alternative embodiment, control unit 22 isconfigured to be able to maintain temperature isolation between one ormore of the fluid circuits so that fluid of differing temperatures maybe delivered from control unit 22 to the outlet ports 24, and thereafterto the thermal pads 32.

By coupling a supply line 30 a to each of these three outlet ports 24and a return line 30 b to each of these three inlet ports 26 of thermalcontrol unit 22, temperature controlled fluid can be delivered fromcontrol unit 22 to three different thermal pads 32. It will beunderstood by those skilled in the art that the number of ports 24 and26 can be varied to include either a smaller or a greater number thanthe three illustrated in FIGS. 1-3. Still further, it will be understoodby those skilled in the art that the ports 24, 26 may be provided invarious physical configuration and combinations to facilitate theconnection and disconnection of the lines 30 a, 30 b and/or thermal pads32. As but one example, instead of using a separate pair of ports 24 and26 for each individual fluid circuit, it is possible to modify controlunit 22 to include a single multi-tube outlet port 24 and a singlemulti-tube inlet port 26 that simultaneously couples and de-couplesmultiple sets of supply lines 30 a and return lines 30 b to and fromcontrol unit 22. Still other variations are possible.

Thermal pads 32 may be any pad, blanket, or other structure adapted tobe positioned in either direct contact or close contact with a patient88. By controlling the temperature of the fluid flowing through hoses 30to thermal pads 32, the temperature of a patient can be controlled viathe close contact of the pads 32 with the patient and the resultant heattransfer therebetween. In one conventional configuration illustrated inFIG. 1, a first thermal pad 32 is wrapped around a patient's torso,while second and third thermal pads 32 are wrapped, respectively, aroundthe patient's right and left legs. Other configurations can be used and,as noted, different numbers of thermal pads 32 may be used with thermalcontrol unit 22, depending upon the number of inlet and outlet ports 26and 24 that are included with thermal control unit 22. Still further, insome embodiments of thermal control system 20, one or more branchingconnectors (not shown) may be coupled to a single pair of inlet andoutlet ports 26 and 24, if desired, so that multiple lines 30 andmultiple thermal pads 32 may be supplied via a single inlet/outlet pair.

Thermal control system 20 also includes, in some embodiments, aplurality of patient temperature probes that are attached to a pluralityof different locations of thermal interest on a patient. Such patienttemperature probes may be any suitable patient temperature probe that isable to sense the temperature of the patient at the location of theprobe. In one embodiment, the patient temperature probes areconventional Y.S.I. 400 probes marketed by YSI Incorporated of YellowSprings, Ohio, or probes that are YSI 400 compliant. In otherembodiments, different types of probes may be used with thermal controlunit 22. Regardless of the specific type of patient temperature probeused in system 20, each temperature probe is connected to a patienttemperature probe port 28 positioned on control unit 22. Patienttemperature probe ports 28 are in electrical communication with acontroller 40 (FIG. 3) that is adapted, in at least some situations, touse the temperature sensed by at least one of the probes in controllingthe temperature of the fluid circulated through control unit 22 and pads32.

Thermal control unit 22 is adapted, in the illustrated embodiment, tooperate in a plurality of different modes that are selectable by a user.In a first mode, known as a manual mode, the thermal control unit 22controls the temperature of the liquid circulating through control unit22—and thereby the temperature of the fluid delivered to thermal pads32—so that it matches a target temperature chosen by the user. In thismode, the control unit 22 maintains the liquid at the chosen targettemperature regardless of the patient's temperature. Indeed, in themanual mode, control unit 22 may be used without any patient temperatureprobes. In a second mode, known as an automatic mode, the thermalcontrol unit 22 controls the temperature of the liquid circulatingthrough control unit 22 in such a manner that a target patienttemperature is achieved and/or maintained. In this automatic mode, atleast one patient temperature probe must be coupled to control unit 22so that control unit 22 knows the patient's current temperature. In theautomatic mode, control unit 22 does not necessarily adjust thetemperature of the circulating fluid to maintain a constant temperature,but instead makes the necessary temperature adjustments to the fluid inorder to effectuate the desired patient temperature.

As shown more clearly in FIG. 2, thermal control unit 22 includes a mainbody 42 to which a removable reservoir 44 is able to be coupled anduncoupled. Removable reservoir 44 is configured to hold the fluid(typically water, although other liquids may be used) that is to becirculated through control unit 22 and the one or more thermal pads 32.By being removable from thermal control unit 22, reservoir 44 can beeasily carried to a sink or faucet for filling and or dumping of thewater or other fluid. This allows users of system 20 to more easily fillcontrol unit 22 prior to its use, as well as to drain thermal controlunit 22 after use. Removable reservoir 44 may further include volumegradations on its outside that provide a visual indication to the userof how much fluid is contained within reservoir 44. The individualgradations may correspond to any appropriate measure of fluid volume,such as, but not limited to, liters, gallons, quarts, fractions thereof,or any other units of fluid volume.

As shown more clearly in FIG. 3, thermal control unit 22 includes a pump46 for circulating fluid through a circulation channel 48. Pump 46, whenactivated, circulates the fluid through circulation channel 48 in thedirection of arrows 50 (clockwise in FIG. 3). Starting at pump 46, thecirculating fluid first passes through heat exchanger 36 where it isdelivered to outlet manifold 38 and its plurality of outlet ports 24. Abypass line 52 is fluidly coupled to outlet manifold 38 and inletmanifold 34. Bypass line 52 allows fluid to circulate throughcirculation channel 48 even in the absence of any thermal pads 32 orlines 30 being coupled to any of outlet and inlet ports 24 and 26. Inthe illustrated embodiment, bypass line 52 includes an optional filter54 that is adapted to filter the circulating fluid. If included, filter54 may be a particle filter adapted to filter out particles within thecirculating fluid that exceed a size threshold, or filter 54 may be abiological filter adapted to purify or sanitize the circulating fluid,or it may be a combination of both.

Inlet manifold 34 includes the plurality of inlet ports 26 that receivefluid returning from the one or more connected thermal pads 32. Theincoming fluid from inlet ports 26, as well as the fluid passing throughbypass line 52, travels back toward the pump 46 into an air separator56. Air separator 56 includes any structure in which the flow of fluidslows down sufficiently to allow air bubbles contained within thecirculating fluid to float upward into a generally vertical tube 58having an air filter 60 at its top end that is exposed to atmosphericpressure. Any air bubbles that are entrained in the circulating fluidwill naturally rise up through vertical tube 58 of air separator 56,pass through air filter 60, and be vented to the atmosphere. Furtherdetails of air separator 56 are provided below with reference to FIG. 4.After passing through air separator 56, the circulating fluid flows pasta valve array 62 positioned beneath fluid reservoir 44 and back to pump46. Valve array 62 is described in greater detail below.

Thermal control unit 22 further includes controller 40 (FIG. 3).Controller 40 is contained within main body 42 and in electricalcommunication with a variety of different sensors and/or actuators. Morespecifically, controller 40 is in electrical communication with pump 46,heat exchanger 36, a control panel 64 (FIG. 1), and one or moretemperature sensors that measure the temperature of the circulatingfluid. Control panel 64 allows a user to operate thermal control unit22, including setting a desired fluid target temperature and/or adesired patient target temperature, and/or to control other aspects ofthermal control unit 22. The temperature sensors provide feedback tocontroller 40 that enables controller 40 to adjust heat exchanger 36, asappropriate, in order to effectuate closed-loop control of thetemperature of the circulating fluid.

Controller 40 includes any and all electrical circuitry and componentsnecessary to carry out the functions and algorithms described herein, aswould be known to one of ordinary skill in the art. Generally speaking,controller 40 may include one or more microcontrollers, microprocessors,and/or other programmable electronics that are programmed to carry outthe functions described herein. It will be understood that controller 40may also include other electronic components that are programmed tocarry out the functions described herein, or that support themicrocontrollers, microprocessors, and/or other electronics. The otherelectronic components include, but are not limited to, one or more fieldprogrammable gate arrays, systems on a chip, volatile or nonvolatilememory, discrete circuitry, integrated circuits, application specificintegrated circuits (ASICs) and/or other hardware, software, orfirmware, as would be known to one of ordinary skill in the art. Suchcomponents can be physically configured in any suitable manner, such asby mounting them to one or more circuit boards, or arranging them inother manners, whether combined into a single unit or distributed acrossmultiple units. Such components may be physically distributed indifferent positions in thermal control unit 22, or they may reside in acommon location within thermal control unit 22. When physicallydistributed, the components may communicate using any suitable serial orparallel communication protocol, such as, but not limited to, CAN, LIN,Firewire, I-squared-C, RS-232, RS-485, universal serial bus (USB), etc.

Controller 40 uses the outputs of the one or more temperature sensors tocontrol the temperature of the circulating fluid such that thecirculating fluid has its temperature adjusted (or maintained) inaccordance with the operating mode (manual or automatic) selected by theuser of thermal control unit 22. Controller 40 may control thetemperature of the fluid using a closed loop proportional-integral (PI)controller, a closed-loop proportional-integral-derivative (PID),controller, or some other type of closed-loop controller.

Further details regarding the construction and operation of thermalcontrol unit 22 that are not described herein are found in commonlyassigned U.S. patent application Ser. No. 14/282,383 filed May 20, 2014,inventors Christopher Hopper et al. and entitled THERMAL CONTROL SYSTEM,the complete disclosure of which is incorporated herein by reference.

Removable reservoir 44 includes a valve 66 on its bottom (FIG. 3) thatautomatically cooperates with a valve 76 within control unit 22 whenreservoir 44 is inserted into thermal control unit 22. Valves 66 and 76may be commercially available valves, such as are available from ColderProducts Company of St. Paul, Minn., or from other suppliers. Bothvalves 66 and 76 automatically close when reservoir 44 is removed fromcontrol unit 22 so that any fluid that is contained within reservoir 44will not leak out of reservoir 44, and any fluid in the control unit 22will not leak out of control unit 22. Valve 76 is part of the valvearray 62 of thermal control unit 22. When removable reservoir 44 isinserted into control unit 22, valves 66 and 76 cooperate with eachother to both open. This automatic opening allows fluid within reservoir44 to flow into control unit 22, depending upon what fluid, if any, isalready present within control unit 22 and the relative pressure of thatfluid compared to any fluid that is contained within reservoir 44.

Generally speaking, a small amount of fluid will flow out of reservoir44 and into thermal control unit 22 when reservoir 44 is initiallyconnected to thermal control unit 22 and pump 46 is not turned on. Thisinitial flow is due to gravity and will continue until the height of thefluid in reservoir 44 approximately matches the height of the fluid inthermal control unit 22. When the heights approximately match, the fluidpressures inside the reservoir and thermal control unit 22 balance andflow stops. When pump 46 is turned on, the fluid inside circulationchannel 48 is pumped out of thermal control unit 22 into one or moreconnected thermal pads 32. As this fluid is pumped out, it is replacedby fluid from within reservoir 44, which flows into circulation channel48. Reservoir 44 continues to replace the pumped fluid until the fluidreturns to inlet manifold 34 and circulating channel 48 is completelyfilled with fluid (as well as the connected thermal pads 32). At thatpoint, no more fluid flows out of reservoir 44.

When pump 46 is initially turned on and fluid from reservoir 44 beginsto fill the entirety of circulation channel 48, fluid lines 30 a and 30b, as well as thermal pad(s) 32, the air that previously occupied thesestructures is vented to atmosphere via air separator 56 (FIGS. 3 and 4).Air separator 56 is shown in more detail in FIG. 4. As noted previously,air separator 56 includes a generally vertical tube 58 having a lowerend 68 and an upper end 70. Vertical tube 58 includes a restrictedregion 72 positioned between upper end 70 and lower end 68. Inside ofvertical tube 58 is a floating plug 74 that floats at different heightsinside of vertical tube 58 depending upon the level of fluid and/orfluid pressure inside of thermal control unit 22. In some embodiments,the fluid level and pressure is such that plug 74 floats belowconstricted region 72 during normal operation of the thermal controlunit 22. In other embodiments, plug 74 may be urged into contact withconstricted region 72 during normal operation, but still allow bubblesto escape by temporarily dropping out of sealing contact withconstricted region 72 when a bubble rises up vertical tube 58. In suchembodiments, plug 74 allows one or more bubbles to escape whilere-engaging constricted region 72 after the escape of such bubbles tothereby prevent liquid from flowing out the top of vertical tube 58.

However, when pump 46 is turned off, any fluid that is contained withinthermal pads 32, fluid lines 30 a and 30 b, and/or the upper regions ofcirculation channel 48 will be pulled downward due to gravity toward thelower regions of circulating channel 48. This back flowing of fluid intocontrol unit 22 causes the fluid level within vertical tube 58 to rise.This rising fluid level similarly causes the height of plug 74 to rise.If the back flow of fluid continues sufficiently, plug 74 eventuallyrises until it reaches constricted region 72. As can be seen in FIG. 4,restricted region 72 has an internal shape that generally matches anupper, external shape of plug 74. The continued rising of plug 74therefore urges plug 74 into contact with restricted region 72 andcreates a seal that prevents further filling of vertical tube 58 withfluid. This prevents fluid from ever rising high enough to escape out ofupper end 70 of vertical tube 58 where it would otherwise spill onto thefloor.

The sealing engagement of plug 74 with restricted region 72 alsoprevents fluid from ever rising in vertical tube 58 to a level where thefluid contacts air filter 60. This helps ensure that air filter 60remains dry, which is generally advantageous in ensuring optimumefficiency of air filter 60. As shown in FIG. 4, air filter 60 ispositioned vertically above constricted region 72. Air filter 60 is opento atmosphere at its top end and allows air inside of vertical tube 58(which comes from within circulation channel 48, hoses 30, and pads 32when they are initially being filled with liquid that forces out the airinside of them) to escape to atmosphere after passing therethrough. Airfilter 60 is, in at least one embodiment, a High-Efficient ParticulateArresting (HEPA) air filter. Such air filters have pores sized to remove99.97% of all particles having a size of 0.3 microns or greater.

In another embodiment, air filter 60 is an Ultra Low Penetration Air(ULPA) filter. Such filters are designed to remove 99.999% ofparticulates having a size of 0.1 microns or larger. Air filter 60 mayalso take on other designs. In some embodiments, air filter 60 is anyair filter that is designed to remove particulates greater than or equalto 0.2 microns. Such filters substantially prevent bacteria orpathogens, such as, but not limited to, mycobacteria, that may haveaerosolized inside of the fluid circuits of thermal control unit 22 fromescaping into the surrounding environment. Air filter 60 therefore helpsensure that any pathogens contained with thermal control unit 22, hoses30, and/or thermal pads 32, remain inside of control unit 22 and do notescape into the ambient surroundings where they could come into contactwith patient 88 or other people.

In the embodiment shown in FIGS. 3-4, plug 74 floats in the fluid andmakes direct sealing contact with constricted region 72. In anotherembodiment, plug 74 does not float directly in the fluid, but rather ismechanically coupled to a float that rises or falls with the rising orfalling fluid level. The mechanical coupling selectively moves the plug74 into sealing engagement with a constricted region. When the float ishigh enough, plug 74 therefore seals off any fluid flow (air or gas)from escaping out of the top end of the air separator. In one of theseembodiments, plug 74 is incorporated into a Honeywell Braukmann EA122aAutomatic Air Vent marketed by Honeywell Corporation of Golden Valley,Minn. In this embodiment, air filter 60 is coupled atop the Honeywellair vent such that air vented out of the Honeywell air vent must firstpass through air filter 60 before being vented to the surroundingatmosphere. Other types of plugs 74 besides the Honeywell air vent maybe used that do not directly float in the liquid.

As is also shown in FIG. 3, thermal control unit 22 also includes acheck valve 78 as part of valve array 62. Check valve 78 is positionedbetween circulation channel 48 and reservoir 44. Check valve 78 is aone-way valve that substantially prevents fluid from flowing out ofchannel 48 and back into reservoir 44. That is, check valve 78 allowsfluid to flow out of reservoir 44 and into circulation channel 48, butdoes not allow fluid to back flow into reservoir 44 from circulationchannel 48. Check valve 78 therefore prevents reservoir 44 from everoverflowing when pump 46 is turned off and gravitational forces urge thefluid inside of hoses 30, thermal pads 32, and/or the upper regions ofcirculation channel 48 toward the lower regions of circulation channel48. This helps ensure that the fluid inside of the fluid circuits doesnot escape into the surrounding environment, including any pathogensthat may be contained within the fluid.

In the embodiment shown in FIG. 3, thermal control unit 22 also includesa fluid reservoir 44 having a lid 82 with a liquid filter 80 integratedtherein. Lid 82 is adapted to be selectively attachable and detachablefrom fluid reservoir 44. Liquid filter 80 and fluid reservoir 44 arealso shown in more detail in FIG. 5. Liquid filter 80 is adapted tofilter the fluid (liquid) that is poured into reservoir 44. In someembodiments, liquid filter 80 is a filter having a pore size of 0.2microns (or otherwise constructed so as to substantially remove allparticulates having a size of 0.2 microns or greater from the fluid thatis poured into reservoir 44). Liquid filter 80 therefore substantiallyremoves all bacteria from the fluid poured into reservoir 44 and helpsprevent the entry and/or growth of bacteria in thermal control system20. Further, liquid filter 80 allows ordinary tap water, rather thandistilled water (or pre-filtered water) to be used with thermal controlunit 22. This eliminates the expense of using distilled water and/or thetime of pre-filtering water prior to pouring it into reservoir 44.

Although not shown, fluid reservoir 44 may also include an air filterintegrated into lid 82, or positioned at another location on fluidreservoir 44. Such an air filter is, in some embodiments, designed tofilter particulates from the air having a size greater than or equal to0.2 microns. The air filter helps ensure that any air that is containedinside of fluid reservoir 44 is filtered prior to being released intothe ambient surroundings. Such air may be released from fluid reservoir44 due to one or more reasons. For example, when reservoir 44 isinitially filled with liquid, some of the air contained therein may beforced into the surrounding atmosphere as the reservoir is filled.Alternatively, check valve 78 may allow relatively small amount of fluidto back flow into reservoir 44 prior to closing, thereby forcing smallamounts of air out of reservoir 44. By including an air filter onreservoir 44, any air that is inside of reservoir 44 and forced out bythe addition of liquid is directed through the air filter prior toescaping to the surrounding environment (lid 82 is adapted, in manyembodiments, to provide a tight fit with the body of reservoir 44 so asto resist air leaking out of reservoir 44 via any gaps between lid 82and the body of reservoir 44).

FIG. 6 illustrates an alternative embodiment of a thermal control unit122. Thermal control unit 122 differs from thermal control unit 22 byincluding a built-in reservoir 144. Built-in reservoir 144, unlikereservoir 44 of thermal control unit 22, is integrated into thermalcontrol unit 122 and not adapted to be removed for filling, emptying,and/or cleaning. Built-in reservoir 144 includes a liquid filter 80 thatoperates in the same manner as liquid filter 80 of reservoir 44. Thatis, liquid filter 80 of built-in reservoir 144 filters liquid, such as,but not limited to water, as a user pours it into built-in reservoir144. Built-in reservoir 144 includes a removable lid 82, in someembodiments, having liquid filter 80 integrated therein. In otherembodiments, built-in reservoir 144 does not include a removable lid 82.Built-in reservoir 144 may additionally include an air filter forfiltering vented air, or it may only include a single combined air andliquid filter that filters incoming liquid and outgoing air.

In at least some embodiments, thermal control unit 122 is constructedsuch that built-in reservoir 144 is positioned to be part of the fluidcircuit. That is, unlike fluid reservoir 44 whose contents are outsideof the fluid circuit of thermal control unit 22, built-in reservoir 144is constructed in some embodiments so that fluid returning from thethermal pads 32 must pass through built-in reservoir 144 before beingpumped back to the thermal pads 32. In at least one of theseembodiments, thermal control unit 122 is modified so that air separator56 is incorporated into built-in reservoir 144. In such embodiments,built-in reservoir 144 includes a constricted region 72 and a plug 74that helps ensure that the built-in reservoir 144 doesn't overflow. Theconstricted region 72 and plug 74 may be constructed in the same mannersas previously described with respect to thermal control unit 22, ormodified in order to accommodate the design of built-in reservoir 144.Further, in some embodiments of thermal control unit 122 in whichbuilt-in reservoir 144 is part of the fluid circuit and includes an airseparator, fluid reservoir 144 also includes an air filter, such as airfilter 60, positioned on top of the air separator in order to filter theair before being vented to the ambient surroundings.

FIGS. 7 and 8 illustrate another alternative embodiment of a fluidreservoir 244 that may be used with thermal control unit 22, or may bebuilt-into thermal control unit 122. Fluid reservoir 244 includes a lid82 that, in some embodiments, is not removable (or requires a specialtool to remove) and that includes a fluid connector 84 integratedtherein. Fluid connector 84 is adapted to mate with a second fluidconnector 86 integrated into the bottom of a fluid container 90. Fluidcontainer 90 also includes a liquid filter 180 integrated therein.Liquid filter 180 is positioned such that any fluid that escapes fromfluid container 90 via second connector 86 must pass therethrough.Liquid filter 180 is adapted to filter out substantially all bacteriathat may be present in the fluid contained within container 90.

Second connector 86 is adapted to prevent fluid from escaping fromcontainer 90 unless second connector 86 is engaged with connector 84 offluid reservoir 244. That is, second connector 86 is adapted to matinglyengage connector 84 and to open up when so engaged. Connector 84 islikewise adapted to open up when engaged by second connector 86 (and toremain closed when not so engaged). Connectors 84 and 86 may take on awide variety of forms. In some embodiments, both connectors areHansen-type quick connect couplings of the type developed by the HansenManufacturing Company (and now a part of Eaton Corporation of Dublin,Ireland). In other embodiments, other types of constructions ofconnectors 84 and 86 may be used.

Regardless of the specific construction of connectors 84 and 86,connectors 84 and 86 are adapted to help ensure that any liquid thatgoes inside of fluid reservoir 244 is filtered prior to entry into fluidreservoir 244. This is accomplished by making connector 84 of fluidreservoir 244 the only entry point for introducing fluid into reservoir244. Thus, in order for a user to fill up fluid reservoir 244, the userfirst fills up container 90 and places container 90 on top of fluidreservoir 244 such that connector 86 engages connector 84. Once thesetwo connectors are engaged, fluid inside of fluid container 90 is freeto drain out of fluid container 90 and into fluid reservoir 244. Inorder for this fluid to drain into fluid reservoir 244, however, it mustpass through liquid filter 180. Fluid reservoir 244 is therefore onlyfilled with fluid that is filtered, thus reducing the likelihood ofbacteria being introduced into thermal control system 20.

Although not illustrated in FIG. 7, fluid reservoir 244 may be modifiedto include an air filter, such as an air filter like air filter 60. Suchan air filter filters air inside of fluid reservoir 244 that isdisplaced by the introduction of liquid into fluid reservoir 244 andvented to the ambient surroundings.

It will be understood by those skilled in the art that a number ofmodifications to the thermal control units 22, 122 disclosed herein maybe made. For example, in some embodiments, check valve 78 is relocatedfrom a location inside of main body 42, such as shown in FIG. 3, to alocation inside of reservoir 44. In one of these embodiments, the checkvalve is positioned at a height such that a predefined amount of fluidmay back flow into the reservoir 44 before the check valve is activated(sealed). For example, in one such embodiment, fluid reservoir 44 isconstructed such that the check valve 78 is positioned generally towardthe top of fluid reservoir 44, thereby allowing fluid to flow back flowinto reservoir 44 until reservoir 44 reaches a threshold level that isalmost full. However, once this threshold level is reached, the checkvalve 78 is closed, thereby preventing any more fluid from back flowinginto the reservoir and thereby preventing the possibility of fluidspilling out of the reservoir 44.

In yet another embodiment, liquid filter 80 of fluid reservoir 44 may berelocated the junction between fluid reservoir 44 and valve array 62such that the liquid inside of fluid reservoir remains unfiltered untilit enters into circulating channel 48. Still other modifications arepossible.

FIG. 9 illustrates a disinfection system 200 according to anotherembodiment of the present disclosure. Disinfection system 200 includes adisinfection station 202 that is adapted to disinfect one or morethermal control units, such as thermal control units 22 and/or 122. Forpurposes of the following description, disinfection system 200 will bedescribed with respect to the disinfection of thermal control unit 22.However, it will be understood that disinfection system 200 can be usedto disinfect thermal control unit 122, including any of the modifiedthermal control unit 22 and 122 discussed above. Still further,disinfection system 200 may be used to disinfect still other types ofthermal control units.

Disinfection station 202 is adapted to fluidly couple to thermal controlunit 22 and supply a disinfection solution to thermal control unit 22.This disinfection solution is run through the inside of thermal controlunit 22 and returned back to disinfection station 202. In somesituations, the user may wish to couple one or more thermal pads 32 tothermal control unit 22 during a disinfection cycle of thermal controlunit 22 such that the disinfection fluid from disinfection station 202is supplied to the pads 32 for disinfecting them. Alternatively oradditionally, the user may wish to couple one or more hoses to thermalcontrol unit 22 such that the disinfection solution from disinfectionstation 202 is run through the hoses during the disinfection cycle andthe hoses are cleaned. In still other situations, reservoir 44 may becoupled to thermal control unit 22 during disinfection, or reservoir 44may be removed during the disinfection cycle and disinfected manually.

As shown more clearly in FIG. 10, disinfection station 202 includes acontroller 204, a user interface 206, a pump 208, a filter 210, adisinfectant reservoir 212, a disinfectant valve 214, an outlet port216, an inlet port 218, a drain port 220, an inflow port 222, an outflowport 224, a plurality of valves 226, and a transceiver 228. Disinfectionstation 202 is fluidly coupled to thermal control unit 22 by way of oneor more hoses 30. Hoses 30 may be the same hoses used to couple thermalcontrol unit 22 to a thermal pad during thermal therapy of a patient,thereby enabling the hoses 30 to be disinfected for later use whendelivering thermal therapy to a patient. One of the supply lines 30 a,30 b couples at one of its ends to outlet port 216 of disinfectionstation 202 and at the other end to one of inlets 26 on thermal controlunit 22. The other of the supply lines 30 a, 30 b couples at one of itsends to inlet port 218 of disinfection station 202 and at its other endto one of outlets 28 of thermal control unit 22.

As shown in FIG. 9, a drain hose 230 is also coupled betweendisinfection station 202 and thermal control unit 22. Drain hose 230 iscoupled at one of its ends to drain port 220 of disinfection station 202and at its other end to a drain port (not shown) on thermal control unit22. The drain port on thermal control unit 22 is positioned at anysuitable location along a bottom of circulation channel 48 such thatsubstantially all fluid within thermal control unit 22 will flow out ofthermal control unit 22 through the drain port when it is opened. Suchoutflow of fluid is accomplished entirely by gravity in someembodiments, and in other embodiments is assisted by way of pump 46 ofthermal control unit 22 and/or pump 208 of disinfection station 202. Insome embodiments, the drain port is a conventional quick connector portthat automatically opens when the coupling at the end of drain hose 230is coupled thereto and automatically closes when drain hose 230 isdecoupled therefrom. At least one of valves 226, which are controlled bycontroller 204, is coupled to drain port 220 and selectively blocksfluid from flowing into disinfection station 202 when the valve isclosed, and allows fluid to flow through drain port 220 and intodisinfection station 202 when the valve is open.

Controller 204 includes one or more microcontrollers suitably programmedto carry out the functions described herein, as well as otherelectronics for carrying out these functions, as would be known to oneof ordinary skill in the art. Controller 204 may additionally, oralternatively, include one or more microprocessors, field programmablegate arrays, systems on a chip, volatile or nonvolatile memory, discretecircuitry, integrated circuits, application specific integrated circuits(ASICs) and/or other hardware, software, or firmware, as would be knownto one of ordinary skill in the art. Such components can be physicallyconfigured in any suitable manner, such as by mounting them to one ormore circuit boards, or arranging them in other manners, whethercombined into a single unit or distributed across multiple units. Suchcomponents may be physically distributed in different positions indisinfection station 202, or they may reside in a common location withindisinfection station 202. When physically distributed, the componentsmay communicate using any suitable serial or parallel communicationprotocol, such as, but not limited to, CAN, LIN, Firewire, I-squared-C,RS-232, RS-485, universal serial bus (USB), etc.

User interface 206 includes a touchscreen display in at least oneembodiment. In other embodiments, other components may be included aspart of user interface 206, such as, but not limited to, one or morebuttons, switches, knobs, or other controls for controlling the variousaspects of disinfection station 202. User interface 206 allows a user tocontrol the operation of disinfection station 202 by communicating usercommands and data to controller 204, which then uses those commands anddata to control valves 226, pump 208, valve 214, and transceiver 228, aswill be discussed in greater detail below.

Disinfection station 202 is utilized by appropriate personnel wheneverit is desired to disinfect one or more thermal control units 22.Disinfection station 202 is used for disinfecting thermal control unit22 by coupling a first hose 30 from outlet port 216 to one of inlets 26on thermal control unit 22 and a second hose from inlet port 218 to oneof outlets 24 on thermal control unit 22. Disinfection station 202 isalso connected to a source of water, via inflow port 222. The source ofwater may be a conventional faucet in the healthcare facility, or it maybe another source of water. In some embodiments, disinfection station202 includes a water reservoir which is manually filled by a user. Thewater, in some embodiments, is distilled water, or other purified water.However, in some embodiments, regular tap water may be used that isdisinfected by disinfection station 202 prior to pumping the fluid tothermal control unit 22. Outflow port 226 of disinfection station 202 isused to drain water from disinfection station 202 after the water hasbeen used to clean thermal control unit 22. In some embodiments, outflowport 224 is coupled to a hose that has its free end coupled to the drainof a sink within the healthcare facility. Fluid flow through outflowport 224 is controlled by one or more of valves 226, which in turn arecontrolled by controller 204.

Prior to commencing disinfection of thermal control unit 22, a usermanipulates one or more controls on user interface 206 to instructdisinfection station 202 to commence a disinfection cycle. In responseto this user command, controller 204 sends instructions to transceiver228 instructing it to establish communication with thermal control unit22. Such communication may be wired or it may be wireless. When wired,any suitable communication protocol may be used, such as, but notlimited to, a USB cable, an Ethernet cable, an RS-485 cable, or stillother types of cables. When wireless, any suitable wirelesscommunication protocol and/or technology may be used, including, but notlimited to, Bluetooth, ZigBee, infrared, etc. In order to carry out suchcommunication, thermal control unit 22 includes an appropriatetransceiver within it (not shown) that is adapted to communicate withtransceiver 228 of disinfection station 202. The transceiver withinthermal control unit 22 is in communication with controller 40 ofthermal control unit 22. The communication between transceiver 228 andthe transceiver of thermal control unit 22 enables controller 204 ofdisinfection station 202 to communicate with the controller 40 ofthermal control unit 22.

The communication between disinfection station 202 and thermal controlunit 22 includes a number of commands and messages. In some embodiments,disinfection station 202 requests and receives from thermal control unit22 a unique identifier that uniquely identifies thermal control unit 22.This unique identifier is stored in memory of disinfection station 202and is displayable on user interface 206. Along with this identifier,controller 204 stores the time and date at which that particular thermalcontrol unit 22 is disinfected by disinfection station 202. This data isstored for each disinfection cycle that each thermal control unit 22undergoes. Disinfection station 202 thereby maintains a record of eachtime each thermal control unit 22 is disinfected. This information isdisplayable on user interface 206, and may be transmitted off-boarddisinfection station 202 to one or more other entities, such as, but notlimited to, one or more servers on a local area network of thehealthcare facility.

Controller 204 may be programmed, in some embodiments, to utilize thedisinfection records of the thermal control units 22 to instructappropriate personnel when it is time to clean one or more thermalcontrol units 22, thereby relieving personnel of the task of determiningwhen a particular thermal control unit 22 should be disinfected. In someembodiments, controller 204 transfers the disinfection record of aparticular thermal control unit 22 to that particular thermal controlunit 22, and a user is able to use the control panel 64 of the thermalcontrol unit 22 to see and review the disinfection history of thatparticular thermal control unit 22. In such embodiments, the thermalcontrol unit 22 may itself calculate when it next needs to bedisinfected, based upon the transpired time since its previousdisinfection, and/or the number and/or amount of usage since the lastdisinfection cycle.

In addition to the aforementioned communication, controller 204 ofdisinfection station 202 also tells controller 40 that a disinfectioncycle is to begin, and that controller 40 should turn on its associatedpump 46 and set a target fluid temperature equal to a specifictemperature. The specific temperature may vary, but in some embodimentsis equal to 25 degrees Celsius. Controller 40 responds to the command bycontrolling heat exchanger 36 in such a manner that the disinfectingsolution received from disinfection station 202 has its temperatureadjusted toward the commanded temperature. Controller 40 also respondsby turning on pump 46 so that the disinfecting solution received fromdisinfection station 202 is pumped through circulation channel 48. Insome embodiments, controller 204 may instruct controller 40 how long tokeep pump 46 turned on and the target temperature maintained. In otherembodiments, controller 204 includes a timer and monitors how long thedisinfecting solution is flowing through thermal control unit 22 and,after a desired time period has elapsed, controller 204 sends a commandto thermal control unit 22 instructing controller 40 to stop its pumpand/or to stop using heat exchanger 36 to meet the target temperature.

In some embodiments, prior to and/or during the pumping of disinfectingfluid from disinfection station 202 to thermal control unit 22, thewater inside of disinfection station 202 is disinfected by adding asuitable amount of disinfectant to the water. The disinfectant ismaintained within disinfectant reservoir 212. Controller 204 controlsdisinfectant valve 214 in such a manner that the appropriate amount ofdisinfectant is added to the fluid within disinfection station 202. Onceadded, controller 204 closes valve 214 so that no further disinfectantis added to the fluid. In some embodiments, controller 204 operates pump208 prior to the hoses 30 being coupled to thermal control unit 22. Theoperation of pump 208 causes fluid to flow internally within acirculation channel 232 inside of disinfection station 202. Circulationchannel 232 flows through pump 208, filter 210, valve 214, outlet port216, a bypass 234, inlet port 218, valves 226, and back to pump 208.Bypass line 234 may include a valve that is operated by controller 204and that opens when fluid is to be pumped internally within disinfectionstation 202 and that closes when fluid is pumped externally from outletport 216 to thermal control unit 22.

In other embodiments, pump 208 need not be operated prior to couplingdisinfection station 202 to thermal control unit 22. In suchembodiments, disinfectant may be added to the water at the same time itis being pumped out of outlet port 216 to thermal control unit 22.Further, in such embodiments, bypass line 234 may be omitted, ifdesired.

During disinfection of thermal control unit 22, water with disinfectantadded to it (disinfecting solution) is pumped from outlet port 216 toone of inlets 26 of thermal control unit 22. The disinfecting solutionthen flows through the inlet 26 port of thermal control unit 22 intoreturn manifold 34. From return manifold 34, the disinfecting solutionis pumped along the entire circulation channel 48 of thermal controlunit 22 until the fluid reaches outlet manifold 38. From there, aportion of the disinfecting solution passes through bypass line 52 andreturns back to return manifold 34. The rest of the disinfectingsolution within outlet manifold 38 is pumped through one of the outlets24 to a hose 30 that is coupled at its other end to disinfecting station202. The fluid then returns to disinfecting station 202 and, in someembodiments, passes again through circulation channel 232 ofdisinfection station 202 (where additional disinfectant may be addedfrom reservoir 212) before being pumped back to thermal control unit 22.In other embodiments, the disinfecting fluid that returns from thermalcontrol unit 22 is diverted to outflow port 224 and discarded.

In other embodiments, rather than having disinfecting solution flow backand forth between thermal control unit 22 and disinfection station 202,the disinfecting solution is initially pumped to thermal control unit 22and remains within thermal control unit 22 until the disinfection timehas expired. In these embodiments, a hose 30 coupling one of outlet 24to disinfection station 202 may be omitted and the return of thedisinfecting solution from thermal control unit 22 to disinfectionstation 202 may be accomplished via drain hose 230. Alternatively, oneor more valves may be included in thermal control unit 22 thatselectively allow and disallow fluid to exit from thermal control unit22 via outlet 24. When so included, controller 40 of thermal controlunit 22 keeps such valves closed during the disinfection cycle. Afterthe disinfecting solution has been pumped internally within circulationchannel 48 of thermal control unit 22 for the desired amount of time,controller 48 opens up one or more of the valves controlling outlet 24.The opening up of one or more of these valves allows fluid to flow outof the outlet 24 and back to disinfecting station 202.

In sum, the supply of disinfecting solution to thermal control unit 22may be implemented in any of at least the three following manners and/orcombinations thereof: (1) pumping disinfecting fluid in a fluid circuitthat includes both disinfection station 202 and thermal control unit 22for a designated time period; (2) pumping disinfecting fluid to thermalcontrol unit 22 where it is pumped and maintained internally withinthermal control unit 22 for a designated time period and then returnedto disinfecting station 202 for drainage via outflow port 224; and/or(3) pumping fluid from inflow port 222 of disinfection station 202 tothermal control unit 22, circulating it therein, and returning it todisinfection station 202 where it is discarded via outflow port 224. Inthe third manner, fresh fluid is continually supplied to disinfectionstation 202 via inflow port 222 during the disinfection period, and thedisinfection solution fluid that returns to disinfection station 202from thermal control unit 22 is continuously discarded via outflow port224.

Regardless of the specific manner in which disinfecting solution issupplied to and circulated through thermal control unit 22, the flow ofdisinfecting solution through thermal control unit 22 continues for apredetermined amount of time. After the predetermined time periodexpires, the disinfecting solution within thermal control unit 22 isdrained therefrom by opening one or more valves 226 associated withdrain port 220, thereby enabling the fluid within thermal control unit22 to drain out to disinfecting station 202 via drain hose 230. Thedrained fluid is discarded by disinfecting station 202 via outflow port224.

After the disinfecting solution has been drained from thermal controlunit 22 and disinfection station 202, the disinfection cycle of thermalcontrol unit 22 may also include a rinse cycle. During the rinse cycle,fresh fluid is supplied to disinfection station 202 via inflow port 222,or manually from a user, or from a fluid reservoir (not shown) containedwithin disinfecting station 202. The fresh fluid is pumped to thermalcontrol unit 22 without the addition of any disinfectant from reservoir212 (or with a reduced amount of disinfectant, or with a differentdisinfectant or additive added thereto). The fresh fluid is thencirculated through thermal control unit for a designated rinse time. Thedesignated rinse time may be the same as the designated time duringwhich disinfecting solution was previously circulated through thermalcontrol unit 22, or it may be for a different amount of time. The supplyand circulation of fresh fluid to thermal control unit 22 during therinse cycle may be accomplished in any of the three different mannerdescribed above for supplying and circulating disinfecting solutionthrough thermal control unit 22. That is, the rinsing fluid may bepumped back and forth in a circuit that includes disinfecting station202 and thermal control unit 22; may be pumped to thermal control unit22 and maintained therein during the entire rinse cycle; and/or may becontinuously supplied via port 222, pumped to thermal control unit 22for rinsing, and continuously drained via outflow port 224 after beingreceived back from thermal control unit 22.

After the rinse cycle has ended, any remaining fluid within thermalcontrol unit 22 is drained via drain hose 230. The drained fluid isreturned to disinfection station 202, which discards the fluid viaoutflow port 224. In some embodiments, multiple disinfection and/orrinse cycles may be implemented, while in other embodiments, only asingle disinfection cycle and rinse cycle is used to clean a thermalcontrol unit 22. After the rinse cycle is completed, in someembodiments, disinfection station 202 supplies an amount of clean fluidto thermal control unit 22 sufficient to enable thermal control unit 22to be used for thermally treating a patient. In this manner, a user doesnot need to manually fill reservoir 44 with fluid to prepare thermalcontrol unit 22 for use with a patient. Instead, disinfection station202 automatically prepares thermal control unit 22 for use. In stillother embodiments, a user can instruct disinfection station 202 via userinterface 206 whether or not to fill thermal control unit 22 withthermal fluid after the rinse cycle is complete. Still further, in someembodiments, controller 204 and/or controller 40 record the time atwhich the rinse cycle was completed, store that time in memory, and makeit available for later viewing by a user and/or for transmission toanother electronic device.

Thermal control unit 22 includes a plurality of inlets 26 and aplurality of outlets 24. As was described above, when thermal controlunit 22 is to be disinfected, a hose 30 is coupled to one of the inlets26 and a hose 30 is coupled to one of the outlets 24. In order todisinfect those inlets and outlets to which no hose 30 is coupled, auser may connect one or more additional hoses to outlets 24 and inlets26. One such hose may have its first end coupled to an outlet 24 and itsother end to an inlet 26. Another hose may similarly have its first endcoupled to another one of the outlets 24 and its other end to anotherone of the inlets 26. The addition of these hoses allows disinfectingfluid and rinsing fluid to flow through the outlets 24 and back throughthe inlets 26 during the disinfection and rinsing cycles, therebyensuring that all of the inlets 26 and outlets 24 are disinfected andrinsed during these cycles.

In some embodiments, disinfecting station 202 is modified to includeonly one port for coupling a hose between disinfection station 202 andthermal control unit 22, such as drain port 220. In these modifiedembodiments, disinfecting station 202 initially supplies disinfectingsolution to thermal control unit 22 by pumping the disinfecting solutionout drain port 220 and through drain hose 230 to thermal control unit22. Once inside thermal control unit 22, the disinfecting solution ispumped by pump 46 through circulation channel 48 for the prescribedamount of time. When the prescribed time has expired, the disinfectingsolution is drained from thermal control unit 22 via drain hose 30 anddiscarded out outflow port 224 of disinfecting station 202. Thereafter,a rinse cycle is completed in the same way, utilizing drain hose 30 tosupply thermal control unit 22 with rinsing fluid and to thereafterdrain away the rinsing fluid when the rinsing cycle is complete.

As shown in FIG. 10, disinfecting station 202 includes a filter 210 thatfilters pollutants from the fluid circulating through disinfectingstation 202. Filter 210 may be a 0.2 micron filter adapted to filter outpollutants having a size greater than 0.2 microns. Alternatively, filter210 may be adapted to filter pollutants having a different size. Filter210 may also, or alternatively, be a set of filters that work togetherto ensure that the fluid supplied to thermal control unit 22 isappropriately filtered. In some embodiments, filter 210 is constructedin accordance with any of the filter arrangements disclosed in commonlyassigned U.S. patent application Ser. No. 62/406,676 filed Oct. 11,2016, by inventors Marko Kostic et al. and entitled THERMAL CONTROLSYSTEM, the complete disclosure of which is incorporated herein byreference. In other embodiments, filter 210 is constructed in differentmanners.

By including filter 210 within disinfection station 202, it is possibleto modify thermal control unit 22 so that it omits one or more offilters 54, 60, and 80. That is, through the regular disinfection of thethermal control unit 22 using disinfection station 202, it may not benecessary or desirable to use one or more filters contained withinthermal control unit 22. The filtering performed by such filters can beeffectively replaced with the filtering action of filter 210 during thedisinfection cycles of the modified thermal control unit 22. In otherwords, the thermal control units can be maintained in a clean state bythe periodic usage of disinfection station 202. Thus, disinfectionstation 202 can be used as a replacement for one or more of filters 54,60, and/or 80. Alternatively, disinfection station 202 can be used as asupplement to these filters whereby the thermal control units includetheir own filters in addition to filter 210 of disinfection station 202.

Disinfection station 202 may be modified to include multiple outletports 216 and inlet ports 218. When such multiple inlet and outlet portsare included, disinfection station 202 is able to simultaneouslydisinfect multiple thermal control units 22. Hoses 30 are coupledbetween the multiple thermal control units 22 and the multiple pairs ofinlet and outlet ports 218 and 216. Disinfecting solution is then pumpedfrom disinfecting station 202 to each thermal control unit 22. In onesuch embodiment, the multiple thermal control units 22 are coupled todisinfecting station 202 in parallel, rather than in series, such thatthe disinfecting solution exiting a particular thermal control unit 22returns directly back to disinfection station 202 rather than beingpumped to another thermal control unit 22 before returning todisinfection station 202.

User interface 206 is configured in some embodiments of disinfectingstation 202 to automatically carry out the entire disinfecting and rinsecycles for a thermal control unit 22 upon pressing a single button onuser interface 206, or otherwise activating a single control on userinterface 206. In this manner, a user merely needs to couple therequisite hoses between thermal control unit 22 and disinfecting station202 and activate the single control. Thereafter, the user does not needto participate in the disinfection cycle and/or rinse cycle. Stillfurther, the user does not need to manually drain either the thermalcontrol unit 22 or the disinfecting station 202. All of these tasks areaccomplished automatically under the control of controller 204 inresponse to the activation of the single control.

Disinfection station 202 may be adapted, in some embodiments, todisinfect different models and/or types of thermal control units 22. Insuch embodiments, disinfection station 202 can be modified to implementdisinfecting and rinsing cycles of different durations, different targettemperatures, and/or of other different variables in order to match theparticular thermal control unit 22 being disinfected by disinfectionstation 202. Information identifying the particular thermal control unit22 to be disinfected may be passed automatically from the controller ofthe thermal control unit 22 to transceiver 228, or it may be manuallyentered by a user into disinfection station 202 using user interface206. As a result, controller 204 of disinfection unit 202 makesappropriate adjustments to the disinfection and/or rinsing cycleassociated with that particular thermal control unit 22.

Disinfection station 202 may be adapted to utilize any of thedisinfection solutions and/or disinfection techniques disclosed incommonly assigned U.S. patent application Ser. No. 15/611,048 filed Jun.1, 2017, by inventors Matthew Ward et al. and entitled METHOD OFDISINFECTING A THERMAL CONTROL UNIT, the complete disclosure of which isincorporated herein by reference.

Various additional alterations and changes beyond those alreadymentioned herein can be made to the above-described embodiments. Thisdisclosure is presented for illustrative purposes and should not beinterpreted as an exhaustive description of all embodiments or to limitthe scope of the claims to the specific elements illustrated ordescribed in connection with these embodiments. For example, and withoutlimitation, any individual element(s) of the described embodiments maybe replaced by alternative elements that provide substantially similarfunctionality or otherwise provide adequate operation. This includes,for example, presently known alternative elements, such as those thatmight be currently known to one skilled in the art, and alternativeelements that may be developed in the future, such as those that oneskilled in the art might, upon development, recognize as an alternative.Any reference to claim elements in the singular, for example, using thearticles “a,” “an,” “the” or “said,” is not to be construed as limitingthe element to the singular.

What is claimed is:
 1. A thermal control unit comprising: a fluidcircuit having a fluid outlet adapted to couple to a fluid supply lineand a fluid inlet adapted to couple to a fluid return line; a reservoirfor supplying a liquid to the fluid circuit, the reservoir positionedoutside of the fluid circuit such that fluid returning from the fluidreturn line is pumped back to the fluid supply line without passingthrough the reservoir; a heat exchanger in the fluid circuit and adaptedto change a temperature of the liquid in the fluid circuit; a pump forcirculating the liquid supplied by the reservoir through the fluidcircuit; a liquid filter coupleable to the reservoir, the liquid filterpositioned such that filling the reservoir with the liquid requirespassing the liquid through the liquid filter when the liquid filter iscoupled to the reservoir; an air eliminator for venting air from thefluid circuit to the ambient surroundings; a first air filter coupled tothe air eliminator, the first air filter adapted to filter particulatesfrom the air vented to the ambient surroundings; a second air filtercoupled to the reservoir, the reservoir being fluidly sealed from theambient surroundings except at a location of the second air filter, thesecond air filter adapted to filter particulates from air vented out ofthe reservoir to the ambient surroundings; and a controller adapted tocontrol the heat exchanger such that a temperature of the circulatingliquid is adjustable toward a desired temperature.
 2. The thermalcontrol unit of claim 1, wherein the air eliminator includes a plughaving a position that varies in response to a level of the liquid inthe thermal control unit, the plug adapted to fluidly isolate the firstair filter from the liquid in the thermal control unit if the level ofthe liquid in the thermal control unit exceeds a threshold.
 3. Thethermal control unit of claim 2, wherein the plug floats in the liquid.4. The thermal control unit of claim 3, wherein the plug rises and fallswith rising and falling levels of the liquid in the thermal controlunit.
 5. The thermal control unit of claim 4, wherein the plug sealinglyengages an aperture when the plug rises past a threshold height, theaperture being positioned between the first air filter and the liquid.6. The thermal control unit of claim 1, wherein the first air filter hasa pore size adapted to filter out particles of 0.2 microns or larger. 7.The thermal control unit of claim 1, wherein the second air filter has apore size adapted to filter out particles of 0.2 microns or larger. 8.The thermal control unit of claim 1, further including a check valvepositioned between the reservoir and the fluid circuit, the check valveadapted to prevent the liquid from flowing out of the fluid circuit andinto the reservoir.
 9. The thermal control unit of claim 1, wherein theliquid filter is integrated into a removable lid adapted to beselectively attached to, and detached from, the reservoir.
 10. Thethermal control unit of claim 9, wherein the reservoir is adapted to belifted out of the thermal control unit without leaking the liquid.
 11. Athermal control unit comprising: a fluid circuit having a fluid outletadapted to couple to a fluid supply line and a fluid inlet adapted tocouple to a fluid return line; a reservoir for supplying a liquid to thefluid circuit; a heat exchanger in the fluid circuit and adapted tochange a temperature of the liquid in the fluid circuit; a pump forcirculating the liquid supplied by the reservoir through the fluidcircuit; a combined air and liquid filter coupled to the reservoir, thecombined air and liquid filter adapted to filter liquid poured into thereservoir and to filter air escaping from the reservoir; an aireliminator for venting air from the fluid circuit to the ambientsurroundings, the air eliminator including an air filter and a plughaving a position that varies in response to a level of the liquid inthe thermal control unit, the air filter adapted to filter particulatesfrom air passing through the air filter, and the plug adapted to fluidlyisolate the air filter from the liquid in the thermal control unit ifthe level of the liquid in the thermal control unit exceeds a threshold;and a controller adapted to control the heat exchanger such that atemperature of the circulating liquid is adjustable toward a desiredtemperature.
 12. The thermal control unit of claim 11, wherein the plugrises and falls with rising and falling levels of the liquid in thethermal control unit, and the plug sealingly engages an aperture whenthe plug rises past a threshold height, the aperture being positionedbetween the air filter and the liquid.
 13. The thermal control unit ofclaim 12, further including a check valve positioned between thereservoir and the fluid circuit, the check valve adapted to prevent theliquid from flowing out of the fluid circuit and into the reservoir. 14.The thermal control unit of claim 11, wherein the combined air andliquid filter is integrated into a removable lid adapted to beselectively attached to, and detached from, the reservoir.